Collisions aren't 2 sided if you enable backface culling. You would need to add the extra poly's in your modeller.
Is your level one big mesh or does it have children. If the later then make sure you set collisions for them too - it is not automatic.
If that doesn't work, can you post your collision set up code and also your main loop?
Stevie
Is your level one big mesh or does it have children. If the later then make sure you set collisions for them too - it is not automatic.
If that doesn't work, can you post your collision set up code and also your main loop?
Stevie